The present invention relates to a display device. More particularly, the invention relates to a planar type display device for displaying images and letters.
Planar type display devices for displaying images and letters are conventionally known, and commercially available devices are arranged to employ birefringence of liquid crystal, electro-luminescence, or plasma light emission, and there are further some in which minute electron guns are disposed in an array manner by a number corresponding to pixels or in which minute optical reflectors are disposed in an array manner by a number corresponding to pixels. Among these devices, those employing liquid crystal are being widely commercialized. A liquid crystal display device applying birefringence of liquid crystal will now be explained herein.
Such a liquid crystal display device might be composed of a liquid crystal panel in which liquid crystal materials are pinched between two opposing substrates, a driving circuit portion for driving the liquid crystal panel, an illuminating device disposed on a rear surface of the liquid crystal panel, and mechanical members for maintaining the liquid crystal panel, the driving circuit portion and the illuminating means in a specified positional relationship. There are also known reflecting type display devices employing sheets for reflecting light which is made incident from the exterior instead of the illuminating device for the purpose of achieving cost reduction, down-sizing and weight reduction.
The mechanical members are mainly formed by employing synthetic resin and metal and generally have an arrangement for mounting the liquid crystal display device to a specified position. In case the arrangement for screwing screws is provided on the members which are to be mounted, the liquid crystal display device will only be formed with screw holes, whereas in case members which are to be mounted are not provided with arrangements for screwing screws, nuts or similar are provided on the liquid crystal display side for enabling screwing of screws.
Taking a case of notebook type personal computers in which liquid crystal displays are being mainly used, a cabinet forming an outermost periphery of a liquid crystal display portion is in many cases made of synthetic resin. Accompanying the widening of liquid crystal display screens in these years, spaces provided for mounting liquid crystal display devices to the synthetic resin cabinets are gradually decreasing. Thus, it is generally the case that arrangements for screwing screws such as nuts are being provided on the liquid crystal display device side in recent thin and narrow-framed liquid crystal display devices.
In the case of notebook type personal computers, not only the liquid crystal display devices are mounted to the synthetic resin cabinets but also one or more circuit members are being simultaneously mounted to the synthetic resin cabinets.
A liquid crystal display device which is mainly used in notebook type personal computers will now be explained. FIGS. 8 to 10 are drawings for illustrating an arrangement of a conventional liquid crystal display device, wherein FIG. 8 is a plan view, FIG. 9 a side view, and FIG. 10 an enlarged view of a section taken along the line Axe2x80x94A in FIG. 8. The liquid crystal display device is generally composed of a liquid crystal panel 3, an optical sheet 6 aiming for improvements in luminance of front side as well as for improvements in display qualities, a light-conducting plate 5 for uniformly introducing light into the liquid crystal display surface, a reflecting sheet 4 for ejecting a large amount of light to the display surface side, a resin frame 1 for holding the optical sheet 6, the light-conducting plate 5 and the reflecting sheet 4, and a thin metallic frame 2 for holding all of the above members. Since the liquid crystal panel 3 is a device which does not emit light, it is necessary to provide for members such as the reflecting sheet 4, wherein these members are referred to as xe2x80x9cbacklightxe2x80x9d as a whole.
In a conventional liquid crystal display device, some dimensional margins in planar directions and thickness directions are left so that various methods might be employed for manufacturing a screwing mechanism to the liquid crystal display device. A popular method employed in the prior art is illustrated in FIG. 10 as one example thereof wherein nuts 7 are embedded in the resin frame 1 of the liquid crystal display device as insert nuts or outsert nuts.
For exhibiting a sufficient strength upon embedding the nuts 7 into the resin frame 1, it will be necessary that sufficient resin is present in peripheries of prepared holes into which the nuts 7 are embedded. However, accompanying rapid developments in liquid crystal display device in these years further thinning and narrow-framing of devices are demanded, so that nuts 7 can no more embedded into the resin frame 1. For example, while nuts 7 having a diameter of approximately 4 mm are required when using screws of M2, the thickness of the resin frame 1 will be approximately 4 mm and thus identical to the outer shape of the nuts 7 in case the entire thickness of the liquid crystal display device is required to be approximately 6 mm, and it is accordingly impossible to embed the nuts 7 into the resin frame 1 as in the prior art.
While it is possible to mount the nuts to the metallic frame 2 through welding, it will not only lead to increased prices but also to remarkably degraded productivity.
It is further the case with notebook type computers that accessory members such as an inverter substrate 11 as illustrated in FIG. 11 are fixed to the synthetic resin cabinet 10 in addition to the liquid crystal display device. In recent displays in which the liquid crystal display portions and outermost shapes of computers are almost identical, a space left for mounting members such as the inverter substrate 11 will be small after mounting the liquid crystal display device to the synthetic resin cabinet 10 to thus make operations for mounting difficult. It will moreover lead to remarkably complicated operations for installing wiring in case a plurality of electronic members are to be mounted into the synthetic resin cabinet 10 to thereby result in poor productivity. It should be noted that 9 denotes the synthetic resin cabinet in the front of the liquid crystal display portion, and 12 a FPC.
The present invention has been made in view of the above facts, and it is an object of the present invention to provide a display device with which it is possible to remarkably improve operability when compared to the prior art and to which a large number of parts might be mounted.
In accordance with the present invention, there is provided a display device comprising a display portion of planar type, electronic parts for driving the display portion through external signals, and mechanical parts for fixing the display portion and the electronic parts to specified positions, wherein the mechanical parts comprise at least thin metallic parts and wherein nuts are either mounted to the metallic parts through calking or metallic parts are directly threaded.